The field of art to which this invention relates is medical devices, more specifically, medical devices and surgical procedures for performing anastomosis of hollow organs such as blood vessels.
Anastomosis surgical procedures are common in the field of cardiac surgery. These procedures are conventionally used for repairing a damaged or diseased blood vessel. In a typical anastomosis procedure, a surgeon joins a first blood vessel to a second blood vessel and creates a passageway between the two blood vessels to provide for the communication of blood flow. For this kind of anastomosis, the surgeon typically uses specialized grasping tools to manipulate a tiny, curved needle attached to an extremely fine surgical filament (e.g., under 0.001 inch diameter) to suture the vessels together. The vessels may be joined conventionally as end-to-end, end-to-side, or side-to-side anastomoses. To facilitate healing of the joined vessels, the prevailing standard of care requires that the surgeon suture the inside surfaces of the first and second vessels together, intima to intima. The surgeon must take great care not to damage the intima of each vessel so that endothelial cells may form over the anastomosis without the formation of thrombus or other complications, thus improving the likelihood of a long term patency of the vessels. For life-saving procedures such as coronary artery bypass graft surgery (CABG), this is especially important. When performing a distal anastomosis in a conventional CABG procedure, the surgeon typically sutures an end-to-side anastomosis of a distal end of a graft vessel (such as, for example, a segment of saphenous vein harvested from the patient) to a side of a target vessel (e.g., the stenosed coronary artery). For a proximal anastomosis in a conventional CABG procedure, the surgeon sutures a proximal end of the graft vessel to the side of the aorta.
As this field of art has progressed, new anastomotic methods have been developed and introduced in attempts to replace the suturing technique briefly described above. Many of these methods incorporate novel fasteners and fastener appliers. The requirement, however, to maintain intima-to-intima contact of the joined vessels remains just as important with these approaches. In fact it is often necessary, prior to joining the vessels, for the surgeon to evert (i.e., turn inside out) the end of at least one of the vessels over the end of a member such as a tube, ferrule, or bushing, etc., which is a component of the fastener or fastener applier. This exposes the intima of that vessel for presentation to the intima of the other vessel prior to fastening the vessels.
Although it is possible to evert larger vessels (over 5 mm in diameter) using standard forceps and graspers available in the operating room, such methods are slow and may result in excessive damage to the vessel everted. And, often the surgeon requires assistance in performing the eversion procedure. Furthermore, vessels smaller than 5 mm are very difficult, if not impossible, to evert using such methods.
There are several requirements for an effective vessel eversion device. As noted earlier, for proper healing, it is important not to injure the intima of either vessel during the eversion procedure. The eversion device also must be easy for the surgeon to use without assistance and require only a few steps to operate. The eversion device must be useful for a wide range of blood vessel sizes, particularly small vessels, e.g., having a diameter of about 2-3 mm or less. In addition, it is desirable for the eversion device to be useful on one end of a vessel, when the opposite end is already attached to the patient (e.g., at the distal anastomosis of a patient undergoing a CABG procedure). The eversion device should also allow for the proper length of everted tissue over the tube, bushing, or the like, depending on the requirements of the anastomosis device/method to be used. Finally, it is desirable that the eversion device be low cost and yet operate reliably.
Accordingly, there is a need in this art for novel devices and methods for engaging and everting the end of a blood vessel (or other tubular body organ) over a member such as a tube, ferrule, bushing, or the like which can be used in a quick and effective manner without causing trauma to the vessel or the intima of the vessel (or tubular body organ).
It is an object of the present invention to provide novel eversion devices which are easy for the surgeon to use without assistance, and which efficiently and effectively engage blood vessels and evert the ends of blood vessels, including blood vessels having small or fine diameters.
A further object of the present invention is to provide novel eversion devices which engage blood vessels and evert the ends of blood vessels without causing trauma to the blood vessel or the intima of the blood vessels.
It is yet another object of the present invention to provide novel methods of engaging and everting blood vessels quickly and efficiently, while preventing or minimizing damage to the blood vessels and the intimas of the blood vessels.
It is still yet a further object of the present invention to provide a novel vessel eversion device and procedure for everting one end of a vessel having the other end already attached to another vessel. Accordingly, an eversion instrument for everting an end of a vessel is disclosed. The instrument has a tubular body member having an axial bore, a distal end and a proximal end. The proximal end has an opening in communication with the axial bore and the distal end has an opening in communication with the axial bore. A piston is slideably contained within the axial bore. The piston has a distal end, a proximal end, and an axial passage. There is a plunger rod member having a distal end and a proximal end. At least a proximal section of the rod member is slideably mounted within the axial passage of the piston and is axially movable between an extended position and a retracted position. A distal end section of the plunger rod extends distally out through the distal opening of the tubular body member. A spring is mounted to the rod member for biasing the plunger with respect to and the piston. The instrument has a plurality of flexible filaments. Each filament has a distal end attached to the distal end of the plunger rod and a proximal end attached to the piston. Each of the filaments is tensioned by the spring biasing the plunger rod with respect to the piston. A plurality of guides circumferentially spaced apart are located at the distal end of the tubular body member. Each guide has a passage for receiving and supporting one or more of the filaments radially apart from the plunger rod. In operation, a distal end section of the plunger and distal end sections of the filaments are insertable into a lumen of a vessel when the plunger rod is in the extended position to evert the end of a vessel.
Another aspect of the present invention is a method of everting the end of a vessel. An eversion instrument is provided. The instrument has a tubular body member having an axial bore, a distal end and a proximal end. The proximal end has an opening in communication with the axial bore and the distal end has an opening in communication with the axial bore. A piston is slideably contained within the axial bore. The piston has a distal end, a proximal end, and an axial passage. There is a plunger rod member having a distal end and a proximal end. At least a proximal section of the rod member is slideably mounted within the axial passage of the piston and is axially movable between an extended position and a retracted position. A distal end section of the plunger rod extends distally out through the distal opening of the tubular body member. A spring is mounted to the rod member for biasing the plunger with respect to and the piston. The instrument has a plurality of flexible filaments. Each filament has a distal end attached to the distal end of the plunger rod and a proximal end attached to the piston. Each of the filaments is tensioned by the spring biasing the plunger rod with respect to the piston. A plurality of guides circumferentially spaced apart are located at the distal end of the tubular body member. Each guide has a passage for receiving and supporting one or more of the filaments radially apart from the plunger rod. A distal end section of the plunger and distal end sections of the filaments are insertable into a lumen of a vessel when the plunger rod is in the extended position. A tubular workpiece is provided. The tubular workpiece has a tubular member having an axial passage, a distal opening and a proximal opening both of which communicate with the axial passage. The tubular member also has an outer surface, a proximal end, and a distal end. Next, a vessel having a lumen is inserted into the axial passage of the tubular member such that an end section of the vessel extends out from the distal end of the tubular member. The distal end section of the plunger and the distal end sections of the filaments are inserted into the lumen of the vessel. The end section of the vessel is then invaginated over the distal end of the distal end of the tubular member onto its outer surface. Then, the end section of the plunger and the distal end sections of the filaments are withdrawn from the lumen of the end section of the vessel. The eversion is completed by withdrawing the everted vessel out from the tubular member.
Yet another aspect of the present invention is the combination of the above-described eversion instrument of the present invention and a tubular workpiece.
These and other aspects and advantages of the present invention will become more apparent from the following description and accompanying drawings.